During his studies, he was an accomplished street performer, and together with friends Richard Fidler and Tim Ferguson, formed a comedy busking trio called the Doug Anthony All Stars.

[1][4] In 1985, Piper left the All Stars to study acting at the Cours Florent in Paris, and was replaced by Paul McDermott.

[5] Piper began his career in humanitarian development in 1989, joining the Australian government aid agency AusAID.

[8] In March 2013, he replaced David Gressly as Regional Humanitarian Coordinator for the Sahel, supporting humanitarian work across the nine countries of the region (Senegal, The Gambia, Chad, Burkina Faso, Niger, Mauritania, Northern Nigeria, Northern Cameroon and Mali).

[7] In December 2018, Piper was appointed Assistant Secretary General of the United Nations Development Coordination Office.